[gsm48] Make method name consistent...

We use rx_rr to indicate that we have received a radio resource
message but one method was using rr_rx. Fix that.
diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index 40505e6..cd883a3 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -1456,7 +1456,7 @@
 }
 
 /* Receive a PAGING RESPONSE message from the MS */
-static int gsm48_rr_rx_pag_resp(struct msgb *msg)
+static int gsm48_rx_rr_pag_resp(struct msgb *msg)
 {
 	struct gsm_bts *bts = msg->lchan->ts->trx->bts;
 	struct gsm48_hdr *gh = msgb_l3(msg);
@@ -1611,7 +1611,7 @@
 		DEBUGP(DRR, "GRPS SUSPEND REQUEST\n");
 		break;
 	case GSM48_MT_RR_PAG_RESP:
-		rc = gsm48_rr_rx_pag_resp(msg);
+		rc = gsm48_rx_rr_pag_resp(msg);
 		break;
 	case GSM48_MT_RR_CHAN_MODE_MODIF_ACK:
 		DEBUGP(DRR, "CHANNEL MODE MODIFY ACK\n");